Concrete Surface Hardener Laboratory Performance Study for Caltrans

California Department of Transportation (Caltrans) is interested in preserving the concrete pavement surface from the wear and abrasion of traffic loading. Especially, on a portion of concrete pavement on Interstate Highway 80 near Truckee area where the pavement deteriorates at an accelerated rate due to snow chains and heavy traffic loading in the truck lanes. Historically, Caltrans has tried thin hot mix asphalt overlay, bonded wearing course, rubberized hot mix asphalt overlay, and micro-surfacing as a fix for these wear problems with various levels of success. Currently, Caltrans is looking for new cost effective concrete surface preservation treatments to solve the wear issues. Concrete surface hardeners may offer a less expensive preservation alternative compared to the previous solutions. There were five different concrete surface hardeners from three companies selected for the laboratory study including Transil Plus and Pentra Sil (IH) from Convergent Concrete, Nano-Lithium 25 from Advan, CS and CLS densifiers from Trinic. Three different tests were performed on the treated and untreated cement mortar surfaces. The concrete surface abrasion test, Caltrans Test Method 550, was used to evaluate the surface abrasion resistance of specimens; Mohs hardness test was used to study the surface hardness changes during the surface hardener treatments; and the rebound hammer test, ASTM C805, was used to evaluate the strengths of various treated and untreated specimens. The statistical testing results were calculated and summarized to show the effectiveness of the surface hardeners on various cement types with different water to cement ratios. The test results showed the levels of effectiveness of different concrete surface hardeners had on the various mix designs.